Deleterious effects produced by various agents, such as ethanol, acetaldehyde and other chemotoxic substances have been found in contractile, regulatory and lattice-forming proteins. These protein systems in liver tissue exist in a dynamic state, one in which the assembly and disassembly of ultrastructural elements permit the varied cell populations in liver tissue to maintain their normal secretory and/or metabolic activity(ies). Control of the assembly of clathrin lattices and their interaction with actin microfilaments and modulatory proteins, like tropomyosin in hepatocytes, permits harmonic interaction of the various ultrastructures for uptake of products at the plasma membrane and their transport to proper destinations in the cytoplasm. Elucidation of the delicate mechanisms existing between these ultrastructural protein systems is essential for an adequate understanding of the deleterious effects that compounds and toxic substances produce on normal liver cells.